The invention relates to a ski binding for cross-country skiing and the like comprising a retaining means for a forwardly extended sole of a ski boot with the use of a holding member holding, in the in-use condition, the extension of the boot sole. Such a binding makes it possible for the boot to be lifted off the ski about a forward transverse axis arranged in front of the toe region of the foot, which is a comfort feature for cross-country skiing, and this is accomplished without the mounting of special fittings, in the toe region of the sole. Furthermore, it is unnecessary to adapt the binding parts to the respective boot size, as is ordinarily the case in cross-country ski bindings for boots without a forward sole extension.
An important aspect of the invention is the solution of the problem of providing a satisfactory, especially firm seating of the sole of the ski boot on the ski with a reliable and simple operation with the use of relatively simple means. A further objective of the invention is the provision of a flawless locking of the binding even if snow is on the ski in the zone of the sole extension.
In particular, the invention is furthermore based on the problem of effecting, in a binding of the aforementioned type, on the one hand a vigorous forward pull of the frontal sole extension into the binding part and thus an especially solid retention of the sole extension and on the other hand a simple locking of the binding by pressure from above and optionally also a simple opening from above, if desired with the aid of the ski pole.
Accordingly, the invention contemplates that guide means are provided for the holding member, adjusting the holding member with respect to the ski from a lifted release position into a lowered in-use position displaced toward the front as compared to the release position so that, during the adjustment operation, the holding member extends behind a projection or a corresponding part at the boot sole extension for the positive entrainment of the boot sole into a forward, tightened position and/or for the positive locking of the boot sole in such a tightened position.
In a particularly preferred embodiment of the invention, the guide means guide the holding member with respect to the surface of the ski in a direction obliquely toward the front with respect to the surface and in an approximately translatory fashion. A resilient holding means is provided for retaining the holding member in an upper locked release position above the sole extension. Guide means are provided which simultaneously exhibit or define a lower locking sole holding position for the holding member. The holding member, after adjustment along the guide means, while overcoming a resistance of the resilient holding means, extends with the aid of a hook-shaped follower behind a counter projection on the sole extension, the pulling direction being oriented toward the front.
For a positive guidance of the holding member, the latter is positively guided in the zone of its front end as well as in the zone of its rear end between its two locking positions.
In a special embodiment of the invention, the guide means are constituted by curved guide tracks on which the holding member is guided from the lifted position into the lowered position.
The guide track or tracks are suitably disposed on the ski side, and the respective guide element on the side of the holding member. However, it is optionally also contemplated to provide a reverse arrangement.
Another special, advantageous embodiment of the invention consists in that the guide means are constituted by one or more guide rods, lever gears, or the like, corresponding from a kinematic viewpoint approximately to the aforementioned curved guide track. It is also contemplated, for example, to arrange a corresponding curved guide slot.
Furthermore, for the guidance of the descending holding member in the forward direction, a guide element, for example a sliding member or--in particularly preferred embodiments--a roller element is provided, which moves, if curved guide tracks are used, along a front guide or control curve track. For the rearward guidance, the hook-shaped follower proper forming part of the holding member can advantageously be utilized in a simple manner.
The following advantages are attained, above all, by the present invention:
Due to the feature that the holding member can be lifted, the skier can step into the binding without any exertion of force. The positive engagement of the sole by means of its extension under a pulling action ensures, on the other hand, that even in case of ice and snow residues in the binding the boot is securely pulled into a locked position and is firmly arrested therein. The act of stepping into the binding can be accomplished without any effort and is enhanced when the binding is locked.
In embodiments where the holding member is guided by a curved track, the curved guide or control track offers the advantage that the curved path can be varied as desired, so that it is possible to obtain a maximally advantageous path of motion for the guide elements, especially rollers. Due to the outside arrangement of the curved guide track (disposed at lateral outside areas of the binding), a reliable optical control is provided to check whether the binding has been duly locked. To securely fix the holding member in the release position or in the in-use sole holding position, the curved guide track or tracks are advantageously constructed to be cam-like with a detent-type upper recess and a detent-type lower recess, engaged by the guide elements in a force-locking fashion under the effect of a spring action. Preferably, a projection extending in the longitudinal direction of the ski over the axis of the roller element or elements is arranged at least above the upper, detent-type recess, so that the stroke of the holding member is safely limited in the upward direction. Especially advantageous is a guidance of the holding member in the forward zone by a curved track extending essentially in a direction vertically to the ski, and in the rearward zone by a guide member exercising its guidance essentially obliquely from the top toward the bottom in the forward direction.
The embodiment with guidance by guide rods offers the advantage, on the other hand, that the holding member is positively guided, independently of the resilient action of the resilient holding means.
In a particularly advantageous embodiment of the invention, the holding member and the supporting or bearing member on the ski side are joined exclusively or practically exclusively by a force-derived (pressure) connection with the aid of a resilient means. An especially simple assembly is made possible by this feature, particularly if tension springs are employed. By overcoming the spring bias, the holding member can be removed from the supporting or bearing member fixedly attached to the ski; this is accomplished by shifting the holding member by depressing the rearward hook-shaped locking element toward the front so that the forward end of the holding member and/or the guide elements thereof can be lifted out of the guide track. Thereby, the supporting or bearing member affixed to the ski and optionally the mounting screws provided at that location for the last-mentioned member are freely accessible for assembly.
To be able to extend behind the sole extension, the holding member preferably comprises a follower and/or locking member acting in the manner of a hook, which is guided, for example, along a guide member for the locking member on the ski side in a direction obliquely downwardly toward the front when the holding member executes a lowering motion.
A particularly simple and compact structure is furthermore attainable if the locking-guide member simultaneously guides the sole extension in the longitudinal direction of the ski. For this purpose, the guide member is advantageously fashioned as a tang-like portion which is defined in a forward section on its underside, for the guidance of the sole extension, by a longitudinal guide surface in parallel or essentially in parallel to the ski, and which is bent obliquely in the upward direction in a rearward section for the rearward guidance of the holding member; this tang-like portion is advantageously formed by bending the supporting member on the ski side.
Guide members, curved guide tracks, and guide elements such as sliding or roller elements are advantageously arranged in pairs on both sides of the longitudinal plane of symmetry of the ski extending vertically to the latter, so that a uniform and stable guidance of the holding member is thus obtained.
Tension springs are provided, for example, as springs for the force-derived connection of the holding member and the supporting member; these tension springs are arranged on both sides of the longitudinal plane of symmetry of the ski extending vertically to the latter. The springs are preferably connected at their front ends to a common axle of roller elements arranged on both sides of the holding member and, on the other hand, are joined to the guide members for the rearward guidance of the holding member.
To provide an easy operation of the binding, making it possible to actuate the binding without the necessity for the skier to stoop down, a cutout accessible from above is arranged in the holding member. This feature makes it possible to place the tip of a ski pole from above into this cutout and couple the tip with the holding member so that the ski pole is usable as a lever arm, substantially rigidly connected to the holding member, to lift the latter and to release the sole extension. Advantageously, the cutout has a stepped portion to give the tip of the ski pole a contact surface to depress the holding member from the release position into the in-use position. Of course, the binding is also constructed so that it can be locked and/or opened manually instead of with the aid of the ski pole.
Even though coil springs are generally especially advantageous with regard to their function and incorporation into the system, particularly if such springs are fashioned as spiral tension springs, it is contemplated to provide instead leaf springs or other kinds of springs.
The rearward guide means for the holding member, preferably fashioned in the form of tangs which are bent inwardly and upwardly toward the rear, can simultaneously serve for limiting the stroke of the holding member in the release position. The arrangement can also be such that a self-locking action of the boot sole with respect to upwardly directed forces is created by a correspondingly inclined positioning of the guide element.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.